As more functionality is embedded into devices that are used in various consumer products, the trend towards portable products suggests an emphasis on conservation of power. As more devices are needed for memory and logic functions, process scaling poses problems that may result in relatively high leakage currents and therefore high standby power consumption.
Many devices require high performance during normal operating modes and may be implemented with thin gate-oxide transistors to achieve the desired performance levels. However, thin gate-oxide transistors may cause relatively large source-to-drain currents that may be undesirably large during standby power modes.
Many devices require that the state of the memory elements be retained during standby modes. This allows the device to resume operation once the device is returned to normal operating mode.